In a typical squeeze film shaft damper arrangement, a shaft with its associated rolling element bearing are permitted to have some limited radial motion in the supporting bearing housing. Ordinarily an annular outer race of a rolling element closely fits in an annular chamber in the support housing where two opposing closely adjacent circumferential surfaces of the housing and race define a thin annular squeeze film space into which an oil under pressure is introduced for damping action.
The use of film dampers in gas turbine engines causes increased clearances for rotor blades and labyrinth seals leading to increased specific fuel consumption (“SFC”) and reduced sealing margins. The effectiveness of the damper is generally improved if the clearance is increased and the damper is sealed. Prior art dampers for turbine engine applications are typically sealed with concentric piston ring type seals which circumferentially engage the bearing housing to seal off the squeeze film space between the rings.
Some prior art dampers are mounted in a centralized spring structure, such as a squirrel cage. This is effective to limit clearances, but the spring structure increases the bearing cost and weight.